This invention relates to surgical devices and methods for dissecting around elongated tissue structures. In particular, this invention relates to devices and methods for dissecting around a blood vessel such as a saphenous vein during an endoscopic vessel harvesting procedure.
Endoscopic vein harvesting (EVH), particularly of the greater saphenous vein in the leg, is a surgical procedure for obtaining a graft vessel for a coronary artery bypass graft (CABG) procedure. A physician""s assistant (PA) typically performs the EVH on one or both legs of the patient while a cardiac surgeon operates on the patient""s chest in preparation for the grafts. Performing the EVH in a timely manner is important so that the PA can present the prepped vessel to the surgeon by the time the surgeon is ready to attach the graft vessel to the heart. The EVH procedure learning curve and additional time required to harvest a blood vessel using minimally invasive techniques continue to be issues for the rapid adoption of the procedure. The present invention improves the ease of use and decreases the time required to harvest a vessel. Specifically, this invention reduces the number of instrument exchanges through the surgical incision in the patient.
Several investigators have proposed devices and methods for performing EVH, as disclosed in the patents cited. For example, U.S. Pat. No. 5,928,138 (xe2x80x9cMethod and Devices for Endoscopic Vessel Harvestingxe2x80x9d, assigned to Ethicon Endo-Surgery, Inc., and issued on Jul. 27, 1999) discloses an optical dissector having a concave working head. A commercial version of this optical dissector is called the ClearGlide subcutaneous retractor and is available from Ethicon, Inc., Somerville, N.J. The ClearGlide is currently one of the main products available today for performing EVH, and provides good access and visibility to the surgical site along the greater saphenous vein.
The PA normally uses the ClearGlide with other endoscopic, surgical dissection instruments in order to isolate the vessel from surrounding tissues. The PA introduces these instruments through a channel provided in the handle and shaft of the ClearGlide in order to operate on tissues within a working space created by a concave working head.
Known methods and devices for performing vessel dissection are discussed in detail in U.S. Pat. Nos. 5,667,480 issued Sep. 16, 1997 and 5,722,934 issued Mar. 3, 1998, both issued to Knight, et al, both of which are incorporated herein by their reference.
Of the known devices and methods for dissection of tissues there remains one constant problem. The problem is that to perform the dissection, extra tools must be inserted along the guide rails of the device through the original incision. Often times this means that to perform a single dissection of a vessel multiple tools must be inserted in succession into the body. Additionally, the harvesting device remains in the body throughout the procedure.
This requirement of inserting the tools in succession and exchanging one tool for another to perform each step of the operation requires extra time, this in turn can be a drain on the individual surgeons resources. Further, because of this increased amount of time, which the surgeon requires to perform the operation, the stress on the patient is increased. Minimization of patient stress is naturally a concern during any surgical procedure. Therefore, the elimination of some or all of the time extending tool exchanges would greatly benefit not only the patient but the surgeon as well.
What is needed, therefore, is a surgical instrument having a concave working head for creating a working space near the vessel to be harvested, and that has at least one dissection element connected to the concave working head. An operator may use the dissection element for dissecting around all sides of the vessel so that it is less necessary to use other dissection instruments. The operator may also use the dissecting element for supporting a tissue structure such as a side branch while it is operated on by another surgical instrument, such as a surgical scissors, ligation instrument, or the like.
The present invention is directed to solving the shortcomings of known vessel retractors, by providing a superior vessel retractor, promoting efficient dissection of vessels, and limiting the stress on patients. The objects of the present invention are the minimization of the tool exchanges, increased efficiency of operation, minimization of patient stress, and increased ease of the overall harvest operation. Further, the present invention pertains to a vessel retractor having a dissecting element. The surgical instrument comprises a spoon retractor having a proximal end and a distal end, said spoon retractor defining a working space in the tissue of a patient, a dissecting element proximate to said spoon retractor for dissecting tissue from a vessel, and means for manipulating said spoon retractor near the vessel. The means for introducing and manipulating the spoon retractor near the vessel comprises, a shaft having a distal end and a proximal end, the distal end of the shaft connected to the proximal end of the spoon retractor, the shaft having a lumen in communication with the working space for insertion of an endoscope there through and a handle connected to a proximal end of the shaft for manipulation of the spoon retractor connected thereto.
The dissecting element may be rigidly fastened to the spoon retractor. In such a configuration the dissecting element comprises a wireform, the wireform comprises a left side rail and a right side rail rigidly connected to the spoon retractor at a proximal end of the wireform, said left and right side rails being connected to each other at a distal end of the wireform and dissecting tissue from the left and right surfaces of the vessel. Additionally the wireform may project upward in the direction of the spoon retractor, and form a U-shape at the distal end of the wireform to facilitate placement of the vessel between the left and right side rails.
The surgical instrument may comprise a control for controlling the dissecting element, when the dissecting element movably connects to the spoon retractor and moves relative to said spoon retractor upon actuation of the control, to facilitate dissection of tissue from the vessel. In such a configuration the dissecting element comprises a movable arm having an extended portion and a shank, the movable arm being rotatable about an axis defined by the shank.
In another configuration the dissection element may comprise a flexible arm slidably retained in said spoon retractor, and movable between an extended position and a retracted position. In such a configuration the distal end of the flexible arm defines at least one curved portion, the curved portion further defining an arm which extends to an outer edge of the flexible arm and facilitating the dissection of tissue from the vessel. The flexible arm is prevented from entering the workspace by guide rails.
Also provided is a method for dissecting a vessel comprising the steps of: providing a surgical instrument for dissecting a vessel in a patient; said surgical instrument comprising a spoon retractor having a proximal end and a distal end; said spoon retractor defining a working space in the tissue of the patient near the vessel to be dissected; a dissecting element proximate to said spoon retractor for dissecting tissue from a vessel; and a means for manipulating said spoon retractor near the vessel, making an incision in a patient; inserting said spoon retractor into the incision; creating a working space in the tissue of the patient near the vessel being dissected; and manipulating said dissecting element to further dissect tissue surrounding the vessel being dissected.
The method further comprises the step of providing a surgical instrument for dissecting a vessel comprising a wireform rigidly attached to the spoon retractor, the wireform comprising a left side rail and a right side rail rigidly connected to the spoon retractor at a proximal end of the wireform, said left and right sides being connected to each other at a distal end of the wireform.
Preferably the manipulating step comprises sliding the wireform along the vessel while the left and rights sides are laterally disposed on the left and right sides of the vessel respectively.
In a configuration where the dissecting element is movably connected to the spoon retractor, the manipulating step may comprise moving the dissecting element relative to said spoon retractor upon actuation of a control.
In a configuration where said dissecting element is a movable arm having an extended portion and a shank, the manipulation may comprise rotating the movable arm about an axis defined by the shank, wherein said manipulating step further comprises sliding the spoon retractor and attached the dissection element along the vessel, and rotating the movable arm about the vessel to dissect the vessel from the surrounding tissue.
The method for dissecting may also comprise using a dissecting element comprising a flexible arm slidably retained in said spoon retractor, and movable between an extended position and a retracted position. Wherein the distal end of the flexible arm defines at least one curved portion, the curved portion further defining an arm which extends to an outer edge of the flexible arm.
In such a configuration the manipulating step preferably comprises, extending the flexible arm from the retracted to the extended position, and sliding the spoon retractor and attached dissection element along the vessel, wherein the curved portion of the flexible arm is placed on at least one side of the vessel to dissect the vessel from the surrounding tissue.